ARM: cleanup lookup_machine_type data and ensure these are placed in __HEAD
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / arm / kernel / head.S
CommitLineData
1da177e4
LT
1/*
2 * linux/arch/arm/kernel/head.S
3 *
4 * Copyright (C) 1994-2002 Russell King
e65f38ed
RK
5 * Copyright (c) 2003 ARM Limited
6 * All Rights Reserved
1da177e4
LT
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * Kernel startup code for all 32-bit CPUs
13 */
1da177e4
LT
14#include <linux/linkage.h>
15#include <linux/init.h>
16
17#include <asm/assembler.h>
18#include <asm/domain.h>
1da177e4 19#include <asm/ptrace.h>
e6ae744d 20#include <asm/asm-offsets.h>
f09b9979 21#include <asm/memory.h>
4f7a1812 22#include <asm/thread_info.h>
1da177e4
LT
23#include <asm/system.h>
24
d4e1c889
LW
25#if (PHYS_OFFSET & 0x001fffff)
26#error "PHYS_OFFSET must be at an even 2MiB boundary!"
27#endif
28
f06b97ff
RK
29#define KERNEL_RAM_VADDR (PAGE_OFFSET + TEXT_OFFSET)
30#define KERNEL_RAM_PADDR (PHYS_OFFSET + TEXT_OFFSET)
9d4f13e5 31
9d20fdd5 32
1da177e4 33/*
37d07b72 34 * swapper_pg_dir is the virtual address of the initial page table.
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RK
35 * We place the page tables 16K below KERNEL_RAM_VADDR. Therefore, we must
36 * make sure that KERNEL_RAM_VADDR is correctly set. Currently, we expect
37d07b72 37 * the least significant 16 bits to be 0x8000, but we could probably
f06b97ff 38 * relax this restriction to KERNEL_RAM_VADDR >= PAGE_OFFSET + 0x4000.
1da177e4 39 */
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RK
40#if (KERNEL_RAM_VADDR & 0xffff) != 0x8000
41#error KERNEL_RAM_VADDR must start at 0xXXXX8000
1da177e4
LT
42#endif
43
44 .globl swapper_pg_dir
f06b97ff 45 .equ swapper_pg_dir, KERNEL_RAM_VADDR - 0x4000
1da177e4 46
37d07b72 47 .macro pgtbl, rd
f06b97ff 48 ldr \rd, =(KERNEL_RAM_PADDR - 0x4000)
1da177e4 49 .endm
1da177e4 50
37d07b72 51#ifdef CONFIG_XIP_KERNEL
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NP
52#define KERNEL_START XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR)
53#define KERNEL_END _edata_loc
37d07b72 54#else
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NP
55#define KERNEL_START KERNEL_RAM_VADDR
56#define KERNEL_END _end
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LT
57#endif
58
59/*
60 * Kernel startup entry point.
61 * ---------------------------
62 *
63 * This is normally called from the decompressor code. The requirements
64 * are: MMU = off, D-cache = off, I-cache = dont care, r0 = 0,
9d20fdd5 65 * r1 = machine nr, r2 = atags pointer.
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66 *
67 * This code is mostly position independent, so if you link the kernel at
68 * 0xc0008000, you call this at __pa(0xc0008000).
69 *
70 * See linux/arch/arm/tools/mach-types for the complete list of machine
71 * numbers for r1.
72 *
73 * We're trying to keep crap to a minimum; DO NOT add any machine specific
74 * crap here - that's what the boot loader (or in extreme, well justified
75 * circumstances, zImage) is for.
76 */
2abc1c50 77 __HEAD
1da177e4 78ENTRY(stext)
b86040a5 79 setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9 @ ensure svc mode
1da177e4 80 @ and irqs disabled
0f44ba1d 81 mrc p15, 0, r9, c0, c0 @ get processor id
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LT
82 bl __lookup_processor_type @ r5=procinfo r9=cpuid
83 movs r10, r5 @ invalid processor (r5=0)?
3c0bdac3 84 beq __error_p @ yes, error 'p'
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85 bl __lookup_machine_type @ r5=machinfo
86 movs r8, r5 @ invalid machine (r5=0)?
87 beq __error_a @ yes, error 'a'
9d20fdd5 88 bl __vet_atags
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89 bl __create_page_tables
90
91 /*
92 * The following calls CPU specific code in a position independent
93 * manner. See arch/arm/mm/proc-*.S for details. r10 = base of
94 * xxx_proc_info structure selected by __lookup_machine_type
95 * above. On return, the CPU will be ready for the MMU to be
96 * turned on, and r0 will hold the CPU control register value.
97 */
a4ae4134 98 ldr r13, =__mmap_switched @ address to jump to after
1da177e4 99 @ mmu has been enabled
b86040a5
CM
100 adr lr, BSYM(__enable_mmu) @ return (PIC) address
101 ARM( add pc, r10, #PROCINFO_INITFUNC )
102 THUMB( add r12, r10, #PROCINFO_INITFUNC )
103 THUMB( mov pc, r12 )
93ed3970 104ENDPROC(stext)
a4ae4134 105 .ltorg
1da177e4 106
e65f38ed 107#if defined(CONFIG_SMP)
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108ENTRY(secondary_startup)
109 /*
110 * Common entry point for secondary CPUs.
111 *
112 * Ensure that we're in SVC mode, and IRQs are disabled. Lookup
113 * the processor type - there is no need to check the machine type
114 * as it has already been validated by the primary processor.
115 */
b86040a5 116 setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9
0f44ba1d 117 mrc p15, 0, r9, c0, c0 @ get processor id
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118 bl __lookup_processor_type
119 movs r10, r5 @ invalid processor?
120 moveq r0, #'p' @ yes, error 'p'
121 beq __error
122
123 /*
124 * Use the page tables supplied from __cpu_up.
125 */
126 adr r4, __secondary_data
b86040a5 127 ldmia r4, {r5, r7, r12} @ address to jump to after
e65f38ed 128 sub r4, r4, r5 @ mmu has been enabled
34d92626 129 ldr r4, [r7, r4] @ get secondary_data.pgdir
b86040a5
CM
130 adr lr, BSYM(__enable_mmu) @ return address
131 mov r13, r12 @ __secondary_switched address
132 ARM( add pc, r10, #PROCINFO_INITFUNC ) @ initialise processor
133 @ (return control reg)
134 THUMB( add r12, r10, #PROCINFO_INITFUNC )
135 THUMB( mov pc, r12 )
93ed3970 136ENDPROC(secondary_startup)
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RK
137
138 /*
139 * r6 = &secondary_data
140 */
141ENTRY(__secondary_switched)
34d92626 142 ldr sp, [r7, #4] @ get secondary_data.stack
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143 mov fp, #0
144 b secondary_start_kernel
93ed3970 145ENDPROC(__secondary_switched)
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146
147 .type __secondary_data, %object
148__secondary_data:
149 .long .
150 .long secondary_data
151 .long __secondary_switched
152#endif /* defined(CONFIG_SMP) */
153
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154
155
156/*
157 * Setup common bits before finally enabling the MMU. Essentially
158 * this is just loading the page table pointer and domain access
159 * registers.
160 */
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161__enable_mmu:
162#ifdef CONFIG_ALIGNMENT_TRAP
163 orr r0, r0, #CR_A
164#else
165 bic r0, r0, #CR_A
166#endif
167#ifdef CONFIG_CPU_DCACHE_DISABLE
168 bic r0, r0, #CR_C
169#endif
170#ifdef CONFIG_CPU_BPREDICT_DISABLE
171 bic r0, r0, #CR_Z
172#endif
173#ifdef CONFIG_CPU_ICACHE_DISABLE
174 bic r0, r0, #CR_I
175#endif
176 mov r5, #(domain_val(DOMAIN_USER, DOMAIN_MANAGER) | \
177 domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \
178 domain_val(DOMAIN_TABLE, DOMAIN_MANAGER) | \
179 domain_val(DOMAIN_IO, DOMAIN_CLIENT))
180 mcr p15, 0, r5, c3, c0, 0 @ load domain access register
181 mcr p15, 0, r4, c2, c0, 0 @ load page table pointer
182 b __turn_mmu_on
93ed3970 183ENDPROC(__enable_mmu)
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184
185/*
186 * Enable the MMU. This completely changes the structure of the visible
187 * memory space. You will not be able to trace execution through this.
188 * If you have an enquiry about this, *please* check the linux-arm-kernel
189 * mailing list archives BEFORE sending another post to the list.
190 *
191 * r0 = cp#15 control register
192 * r13 = *virtual* address to jump to upon completion
193 *
194 * other registers depend on the function called upon completion
195 */
196 .align 5
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LT
197__turn_mmu_on:
198 mov r0, r0
199 mcr p15, 0, r0, c1, c0, 0 @ write control reg
200 mrc p15, 0, r3, c0, c0, 0 @ read id reg
201 mov r3, r3
b86040a5
CM
202 mov r3, r13
203 mov pc, r3
93ed3970 204ENDPROC(__turn_mmu_on)
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205
206
207/*
208 * Setup the initial page tables. We only setup the barest
209 * amount which are required to get the kernel running, which
210 * generally means mapping in the kernel code.
211 *
212 * r8 = machinfo
213 * r9 = cpuid
214 * r10 = procinfo
215 *
216 * Returns:
2df96b34 217 * r0, r3, r6, r7 corrupted
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218 * r4 = physical page table address
219 */
1da177e4 220__create_page_tables:
37d07b72 221 pgtbl r4 @ page table address
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222
223 /*
224 * Clear the 16K level 1 swapper page table
225 */
226 mov r0, r4
227 mov r3, #0
228 add r6, r0, #0x4000
2291: str r3, [r0], #4
230 str r3, [r0], #4
231 str r3, [r0], #4
232 str r3, [r0], #4
233 teq r0, r6
234 bne 1b
235
8799ee9f 236 ldr r7, [r10, #PROCINFO_MM_MMUFLAGS] @ mm_mmuflags
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LT
237
238 /*
239 * Create identity mapping for first MB of kernel to
240 * cater for the MMU enable. This identity mapping
241 * will be removed by paging_init(). We use our current program
242 * counter to determine corresponding section base address.
243 */
b86040a5
CM
244 mov r6, pc
245 mov r6, r6, lsr #20 @ start of kernel section
1da177e4
LT
246 orr r3, r7, r6, lsl #20 @ flags + kernel base
247 str r3, [r4, r6, lsl #2] @ identity mapping
248
249 /*
250 * Now setup the pagetables for our kernel direct
2552fc27 251 * mapped region.
1da177e4 252 */
e98ff7f6
NP
253 add r0, r4, #(KERNEL_START & 0xff000000) >> 18
254 str r3, [r0, #(KERNEL_START & 0x00f00000) >> 18]!
255 ldr r6, =(KERNEL_END - 1)
256 add r0, r0, #4
257 add r6, r4, r6, lsr #18
2581: cmp r0, r6
259 add r3, r3, #1 << 20
260 strls r3, [r0], #4
261 bls 1b
1da177e4 262
ec3622d9
NP
263#ifdef CONFIG_XIP_KERNEL
264 /*
265 * Map some ram to cover our .data and .bss areas.
266 */
267 orr r3, r7, #(KERNEL_RAM_PADDR & 0xff000000)
40435792 268 .if (KERNEL_RAM_PADDR & 0x00f00000)
ec3622d9 269 orr r3, r3, #(KERNEL_RAM_PADDR & 0x00f00000)
40435792 270 .endif
ec3622d9
NP
271 add r0, r4, #(KERNEL_RAM_VADDR & 0xff000000) >> 18
272 str r3, [r0, #(KERNEL_RAM_VADDR & 0x00f00000) >> 18]!
273 ldr r6, =(_end - 1)
274 add r0, r0, #4
275 add r6, r4, r6, lsr #18
2761: cmp r0, r6
277 add r3, r3, #1 << 20
278 strls r3, [r0], #4
279 bls 1b
280#endif
281
1da177e4
LT
282 /*
283 * Then map first 1MB of ram in case it contains our boot params.
284 */
f09b9979 285 add r0, r4, #PAGE_OFFSET >> 18
d4e1c889 286 orr r6, r7, #(PHYS_OFFSET & 0xff000000)
40435792
NP
287 .if (PHYS_OFFSET & 0x00f00000)
288 orr r6, r6, #(PHYS_OFFSET & 0x00f00000)
289 .endif
1da177e4
LT
290 str r6, [r0]
291
c77b0427 292#ifdef CONFIG_DEBUG_LL
8799ee9f 293 ldr r7, [r10, #PROCINFO_IO_MMUFLAGS] @ io_mmuflags
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294 /*
295 * Map in IO space for serial debugging.
296 * This allows debug messages to be output
297 * via a serial console before paging_init.
298 */
299 ldr r3, [r8, #MACHINFO_PGOFFIO]
300 add r0, r4, r3
301 rsb r3, r3, #0x4000 @ PTRS_PER_PGD*sizeof(long)
302 cmp r3, #0x0800 @ limit to 512MB
303 movhi r3, #0x0800
304 add r6, r0, r3
305 ldr r3, [r8, #MACHINFO_PHYSIO]
306 orr r3, r3, r7
3071: str r3, [r0], #4
308 add r3, r3, #1 << 20
309 teq r0, r6
310 bne 1b
311#if defined(CONFIG_ARCH_NETWINDER) || defined(CONFIG_ARCH_CATS)
312 /*
3c0bdac3
RK
313 * If we're using the NetWinder or CATS, we also need to map
314 * in the 16550-type serial port for the debug messages
1da177e4 315 */
c77b0427
RK
316 add r0, r4, #0xff000000 >> 18
317 orr r3, r7, #0x7c000000
318 str r3, [r0]
1da177e4 319#endif
1da177e4
LT
320#ifdef CONFIG_ARCH_RPC
321 /*
322 * Map in screen at 0x02000000 & SCREEN2_BASE
323 * Similar reasons here - for debug. This is
324 * only for Acorn RiscPC architectures.
325 */
c77b0427
RK
326 add r0, r4, #0x02000000 >> 18
327 orr r3, r7, #0x02000000
1da177e4 328 str r3, [r0]
c77b0427 329 add r0, r4, #0xd8000000 >> 18
1da177e4 330 str r3, [r0]
c77b0427 331#endif
1da177e4
LT
332#endif
333 mov pc, lr
93ed3970 334ENDPROC(__create_page_tables)
1da177e4
LT
335 .ltorg
336
75d90832 337#include "head-common.S"